Rotary cooler and the like

ABSTRACT

A rotary cooler is disclosed having a cylindrical shell mounted to rotate about its central axis. The interior of the shell is provided with parts assembled in groups to divide the interior cells. Each of the cell defining assemblies include a pair of wall structures and each wall structure has a radially inward projecting and axially extending surface forming a scoop which in end view is a J-shaped having a back portion, a bottom portion and a lip portion defining a pocket therebetween. Each wall structure is arranged with the pocket on an end thereof projecting radially inward, and the back portion remote of the pocket is pivotally connected at longitudinally spaced locations to the inner periphery of the cooler shell by a pin parallel to the central axis of the cooler shell. The radially inner end of each wall structure is connected at longitudinally spaced locations to one adjacent wall structure by a hinge. Each hinge has a midhinge pivot pin parallel to the central axis of the cooler shell. Thus each hinge has a pivot pin which is part of cell defining assembly with two parallel pins at the inner periphery of the cooler shell and each such group of three pins provides pivotal and axially slidable connections that accommodate movement of the parts of their cell defining assembly relative to each other and relative to the shell upon thermal expansion of the parts without rupturing such parts.

United States Patent inventors Robert M. Bliemeister;

Ellis P. Hansen, Milwaukee, Wis.; David P. Lehman, New Martinsville, W. Va. Appl. No. 877,967 Filed Nov. 19, 1969 Patented Apr. 27, 1971 Assignee Allis-Chalmers Manufacturing Company Milwaukee, Wis.

ROTARY COOLER AND THE LIKE 9 Claims, 3 Drawing Figs.

US. Cl 34/109, 34/135, 34/142, 259/3 Int. Cl F26b 11/06 Field of Search 34/108, 109, 115, 134, 135, 142; 259/(lnquired); 68/(Inquired) References Cited UNITED STATES PATENTS 1,557,475 10/ 1 925 Jorgensen 34/109 8/1962 Erisman etal. 34/136 3,245,154 4/1966 Bovner et a1 34/ l 35X Primary Examiner-Frederick L. Matteson Assistant Examiner-Theophil W. Streule Attorneys-Arthur M. Streich, Robert B. Benson and John P.

Hines ABSTRACT: A rotary cooler is disclosed having a cylindrical shell mounted to rotate about its central axis. The interior of the shell is provided with parts assembled in groups to divide the interior cells. Each of the cell defining assemblies include a pair of wall structures and each wall structure has a radially inward projecting and axially extending surface forming a scoop which in end view is a .I-shaped having a back portion, a bottom portion and a lip portion defining a pocket therebetween. Each wall structure is arranged with the pocket on an end thereof projecting radially inward, and the back portion remote of the pocket is pivotally connected at longitudinally spaced locations to the inner periphery of the cooler shell by a pin parallel to the central axis of the cooler shell. The radially inner end of each wall structure is connected at longitudinally spaced locations to one adjacent wall structure by a hinge. Each hinge has a midhinge pivot pin parallel to the central axis of the cooler shell. Thus each hinge has a pivot pin which is part of cell defining assembly with two parallel pins at the inner periphery of the cooler shell and each such group of three pins provides pivotal and axially slidable connections that accommodate movement of the parts of their cell defining assembly relative to each other and relative to the shell upon thermal expansion of the parts without rupturing such parts.

ROTARY COOLER AND THE LIKE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to rotary heat exchangers such as are used to heat, cool and dry material with a gas, and in particular to recuperative rotary coolers which are internally divided into compartments or cells and which may be used for such purposes as air cooling alumina discharged from a rotary kiln and returning the heat absorbed by the air from the material, back to the kiln and the process by using such heated air as combustion air in the kiln.

2. Description of the Prior Art Rotary recuperative heat exchangers may be classified for the present discussion, as comprising five types. A first of such types may be considered as including coolers such as shown in U.S. Pat. No. 1,883,722, which comprises a single rotating cylinder with or without lifter flights.

A second, third, fourth and fifth type all relates to various ways the interior of a cylindrical shell may be subdivided into compartments or cells. As a second type we may consider those as shown in U.S. Pat. No. 2,851,792, which have at least at some locations along the length of the kiln, the entire interior divided into cells, all of which at some time during rotation are intended to contain both hot material and cooling air.

A third type may be those in which an outer ring of air cells surround a central tube, with the material being substantially confined within the central tube and the air blown tangentially therethrough from the outer ring. Typical of the patents showing that type are U.S. Pat. No. 2,483,630, U.S. Pat. No. 2,581,756 and U.S. Pat. No. 3,050,868. 1

A fourth type may be those having a central tube providing support for an outer ring of structures defining cells for hot material and with at least some flow of cooling air but substantially no hot material moving through the central tube and no air moving radially inwardly or outwardly through the tube. Typical of patents showing that type are U.S. Pat. No. 2,666,633 and U.S. Pat. No. 2,818,657.

A fifth type is one which may have central support for an outer ring of cells with the hot material substantially confined to the outer ring of cells, but which does have an air flow through a central tubular passage that provides for a radial movement of air as well as air movement axially through the central passage. Typical of patents showing such types are U.S. Pat. No. 1,995,966 and U.S. Pat. No. 2,746,170.

Many of the foregoing types are discussed, with advantages and problems being pointed out, in the first two installments of a three part series by Wolf G. Bauer in the trade journal Pit and Quarry," entitled The Art of Recuperative Cooling," with Part I appearing in May, 1964, Part II in June 1964 and Part III in July, I964. In this series, and particularly in Part II, a design approach is recommended for cell defining walls which the present inventors found did not survive the alternating heating and cooling that results from handling high temperature materials such as alumina discharged from a rotary kiln. It is to this problem that the present invention is directed and a solution thereto is its principal object.

SUMMARY OF THE PRESENT INVENTION According to a preferred embodiment of the present invention a rotary cooler having a cylindrical shell mounted to rotate about its central axis is provided with parts assembled in groups to divide the interior of the shell into cells. Each of the cell defining assemblies include a pair of arcuately spaced apart wall structures and each wall structure has a radially inward projecting and longitudinally extending surface forming a scoop which in end view is a J-shape having a back portion, a bottom portion and a lip portion defining a pocket therebetween. Each wall structure is arranged with the pocket on an end thereof projecting radially inward, and the back portion remote of the pocket is pivotally connected at longitudinally spaced locations to the inner periphery of the cooler shell by a pin parallel to the central axis of the cooler shell.

The radially inner end of each wall structure is connected at longitudinally spaced locations to one adjacent but arcuately spaced wall structure by a hinge. Each hinge has a midhinge pivot pin parallel to the central axis of the cooler shell. Thus each hinge has a pivot pin which is part of cell defining assembly with two parallel pins at the inner periphery of the cooler shell and each such group of three pins provides pivotal connections that accommodate movement of the parts of their cell defining assembly relative to each other and relative to the shell upon alternate thermal expansion and contraction of the parts without rupturing such parts.

Other features and objects of the invention that have been attained will appear from the more detailed description to follow with reference to an embodiment of the present invention shown in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 of the accompanying drawing shows a side elevation, partly in section, of a rotary cooler according to the present invention;

FIG. 2 is a view taken along line lI-II in FIG. 1 and viewing the structure in the direction indicated by arrows; and

FIG. 3 is a diagram illustrating the movement of certain parts upon thermal expansion and contraction.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a cylindrical shell 1 is mounted on rollers 2 for rotation of shell 1 about a central axis x-x. The shell 1 has a material inlet end provided with a feed hood 3 having a supply chute 4 projecting therethrough into shell land an out let 5 for discharging air used to cool material in shell I and which in a recuperative system will be delivered to a rotary kiln (not shown) as preheated combustion supporting air. At the material outlet end of shell 1 a discharge hood 6 is provided and has a material outlet 7 for cooled material and a gas inlet 8 for cooling air. The interior of shell 1 is provided with parts grouped into assemblies which can be best described with reference to FIG. 2.

FIG. 2 shows a plurality of parts within shell I grouped, in a manner that will be described, in assemblies defining a ring of cells 11 around the inner periphery of shell 1 and a central axially extending gas passage l2. Each of the assemblies defining the cells 11 comprise a pair of arcuately spaced wall structures 15, 15a. Each of the wall structures 15, 15a has a radially inward and axially extending surface 16. A bottom surface 17 projects transversely from a location at or near the radially inner end of radial surface 16. A lip surface 18 projects radially outward from the end of surface 17 remote from surface 16 has a terminal edge 19 spaced from the inner periphery of the cooler shell 1. The surfaces 16, 17, 18 and the edge 19 of wall structure 15, when viewed in end view as in FIG. 2, present a configuration of a J-shapedl scoop. A pocket 20 is therefore defined between the radially inner portion of radial surface 16, the bottom surface 17 and the lip surface 18. The lip surface 18 of wall structure 15 is both substantially parallel to and spaced apart a small distance from the radial surface 16a of an adjacent and arcuately spaced wall structure 150.

Each of the wall structures 15 is attached to the inner periphery of shell 1 by a pivotal connection 24. The pivotal connection includes a support block 25 welded to the inner surface of shell 1, and having a bore through which a pivot pin 27 passes. Radially extending braces 26 welded to radial surface 16 are also provided with a bore through which pivot pin 27 passes, thus pin 27 pivotally connecting each block 25 to a brace 26. Such pivotal connections 24 may be provided at axially spaced locations as shown in FIG. I.

A crossmember, disclosed in FIG. 2 as being a hinge 30, connects the radially inner end of each radial wall surface 16 to one arcuately spaced and next adjacent radial wall surface, as for example surface 16a, to provide linked pairs of radial wall surfaces 16, 16a. The hinge 30 is radially inward of the surfaces 17 and 18 that define the pocket 20. The hinge 30 comprises a pair of end pieces 31, 32 pivotally linked by a midhinge pivot pin 33 which is intermediate the radial surfaces 16, 16a of each such linked pair of such surfaces, and pin 33 is parallel to the pins 27 and the central axis x-x of the cooler shell 1'. Such a crossmember hinge 30 may be provided at axially spaced locations as shown in FIG. 1.

As much of the present invention as has been thus far described, operates in a manner that will now be described. During operation of the apparatus of FIG. 1, material to be cooled such as hot alumina discharged from a rotary kiln, is fed by chute 4 into the feed end of shell 1. Because of the very high temperature of such material the shell may be lined with refractory material 40, as shown in FIG. 2. Hot material is caught by the wall structure 15 and as the shell rotates in the direction indicated by arrows in FIG. 2, and the material is subdivided with portions of the feed from chute 4 passing into the cells 11. As the cooler shell 1 rotates about its central axis x-x the material is given a rotary motion within each cell and the moving hot material covers and uncovers surfaces and portions of surfaces defining the cells 11 and pockets 20, resulting in alternate heating and cooling thereof which has results that will be described in greater detail later with reference to FIG. 3. As material moves through the cooler shell 1 shown in FIG. 1 from chute 4 to the material outlet 7, it is cooled by air admitted at the gas inlet 8. The air that cools the material is itself heated in the process of doing so and is discharged through air outlet 5, for delivery to a kiln as preheated combustion air.

Referring now to FIG. 3, the effect of the alternate exposure to hot material and cool air, with resulting alternate expansion and contraction, will now be described. In FIG. 3 two cells 11 are shown and the cool or contracted position of wall structures l and 15a and hinge are indicated with solid lines while their hot or expanded position (exaggerated) is shown with broken lines. It is there shown how expansion increases the radial length of the radial wall surfaces 16, 16a and the transverse length of hinge 30. FIG. 3 also shows by the position of the broken lines that the radial wall surfaces 16, 16a turn about pivot pins 27, 27a to move away from each other and at the same time midhinge pivot pin 33 may move radially inward, with end pieces 31, 32 forming a slight V-shape, as hinge 30 expands. Sidewalls l5 and 15a may similarly expand differentially, in which case pin 33 may move along its own central axis. Thus three pins 27, 27a and 33 provide pivotal axes for accommodating movement of the assembly of parts that has been described, upon alternate thermal expansion and contraction of the parts without rupturing such parts.

From the foregoing detailed description of the present invention, it has been shown how the objects of the invention have been attained in a preferred manner. However, modifications and equivalents of the disclosed concepts such as readily occur to those skilled in the art are intended to be included within the scope of this invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

We claim:

1. In a rotary cooler having a cylindrical shell mounted to rotate about a central axis sloped downwardly slightly to facilitate movement of material through the shell and a plurality of parts within said shell grouped into assemblies defining material confining cells arranged around the inner periphery of the shell and defining radially inward thereof a central axially extending gas passage, an improvement comprising:

each of the cell defining assemblies having a pair of arcuately spaced walls each having a radially inward projecting and axially extending surface; I a pivotal connection at a radially outer end of each wall connecting the wall to the inner periphery of the shell and having a pivotal axis parallel to said central axis; and a crossmember connecting the radially inner end of each radial wall surface to one arcuately spaced next adjacent radial wall surface to provide linked pairs thereof, said crossmember having a pivot intermediate the ends of the crossmember with a pivotal axis parallel to said central axis to provide for each linked pair of radial wall surfaces, one pivotal axis between the radially inner ends of the radial wall surfaces of each said linked pair, and a pair of arcuately spaced pivotal axes for the radially outer ends of each linked pair of radial wall surfaces, which cooperate to accommodate movement of such parts relative to each other and relative to the shell upon alternate thermal expansion and contraction of such parts. 2. In a cooler according to claim 1, each of said walls having a scoop forming portion on the radially inner end thereof and.

the walls having a configuration therewith which in end view is J-shaped.

3. ln a cooler according to claim 2, the scoop forming portion includes a bottom surface projecting transversely from a portion of the radially inner end of the radial surface of the wall, and a lip surface projecting radially outward from the end of the bottom surface remote from the radial surface of the wall.

4. ln a cooler according to claim 3 said lip having a terminal edge spaced from the inner periphery of the cooler shell.

5. In a cooler according to claim 4 said lip being substantially parallel to and spaced from the radial surface of the next adjacent wall.

6. In a cooler according to claim 3, said bottom surface of the scoop forming portion being radially outward of the crossmember connecting the walls of each cell defining pair of walls.

7. In a cooler according to claim 1, said crossmember comprising a hinge having a midhinge pivot pin parallel to the central axis of the cooler shell.

8. In a cooler according to claim 7, each said pivotal connection at the radially outer end of each wall including a pivot pin parallel to said hinge pivot pin.

9. ln a cooler according to claim 1, said radially inward and axially extending surfaces each having at least a pair of said pivotal connections with the inner periphery of the cooler shell, with said pivotal connections being spaced apart along a radially outer edge thereof parallel to the central axis of the cooler shell, and a pair of said crossmembers, with said crossmembers being spaced apart along a radially inner edge thereof parallel to the central axis of the cooler shell. 

1. In a rotary cooler having a cylindrical shell mounted to rotate about a central axis sloped downwardly slightly to facilitate movement of material through the shell and a plurality of parts within said shell grouped into assemblies defining material confining cells arranged around the inner periphery of the shell and defining radially inward thereof a central axially extending gas passage, an improvement comprising: each of the cell defining assemblies having a pair of arcuately spaced walls each having a radially inward projecting and axially extending surface; a pivotal connection at a radially outer end of each wall connecting the wall to the inner periphery of the shell and having a pivotal axis parallel to said central axis; and a crossmember connecting the radially inner end of each radial wall surface to one arcuately spaced next adjacent radial wall surface to provide linked pairs thereof, said crossmember having a pivot intermediate the ends of the crossmember with a pivotal axis parallel to said central axis to provide for each linked pair of radial wall surfaces, one pivotal axis between the radially inner ends of the radial wall surfaces of each said linked pair, and a pair of arcuately spaced pivotal axes for the radially outer ends of each linked pair of radial wall surfaces, which cooperate to accommodate movement of such parts relative to each other and relative to the shell upon alternate thermal expansion and contraction of such parts.
 2. In a cooler according to claim 1, each of said walls having a scoop forming portion on the radially inner end thereof and the walls having a configuration therewith which in end view is J-shaped.
 3. In a cooler according to claim 2, the scoop forming portion includes a bottom surface projecting transversely from a portion of the radially inner end of the radial surface of the wall, and a lip surface projecting radially outward from the end of the bottom surface remote from the radial surface of the wall.
 4. In a cooler according to claim 3 said lip havIng a terminal edge spaced from the inner periphery of the cooler shell.
 5. In a cooler according to claim 4 said lip being substantially parallel to and spaced from the radial surface of the next adjacent wall.
 6. In a cooler according to claim 3, said bottom surface of the scoop forming portion being radially outward of the crossmember connecting the walls of each cell defining pair of walls.
 7. In a cooler according to claim 1, said crossmember comprising a hinge having a midhinge pivot pin parallel to the central axis of the cooler shell.
 8. In a cooler according to claim 7, each said pivotal connection at the radially outer end of each wall including a pivot pin parallel to said hinge pivot pin.
 9. In a cooler according to claim 1, said radially inward and axially extending surfaces each having at least a pair of said pivotal connections with the inner periphery of the cooler shell, with said pivotal connections being spaced apart along a radially outer edge thereof parallel to the central axis of the cooler shell, and a pair of said crossmembers, with said crossmembers being spaced apart along a radially inner edge thereof parallel to the central axis of the cooler shell. 